(1) Field of the Invention
This invention relates to a disk cartridge using a flexible cartridge case or a cartridge case molded from a synthetic resin, for example, a magnetic disk cartridge, etc., and particularly to a cleaning sheet for the disk cartridge.
(2) Prior Art
A disk cartridge, for example, a magnetic disk cartridge, mainly comprises a cartridge case having openings for inserting magnetic heads and openings for inserting a rotation driving shaft, a flexible magnetic disk rotatably encased in the cartridge case, and a cleaning sheet supported on the inside surfaces of the cartridge case.
The cleaning sheet for the conventional magnetic disk cartridge is composed of a non-woven fabric made of, for example, mixed fibers of rayon and polypropylene, mixed fibers of rayon and polyethylene terephthalate, or single fibers of polyethylene terephthalate, and is fixed to the inside surfaces of a cartridge case by heat welding or by an adhesive.
The cleaning sheet must have two kinds of characteristics, i.e. disk-handling characteristics such as the ability to not damage a disk such as a magnetic disk, a distinguished capability to clean the disk, etc., and cartridge case-fixing characteristics such as adhesiveness and weldability.
However, the cleaning sheets composed of the aforementioned fibers do not have good capability to clean the magnetic disk, and further have such problems as causing the development of scratches on the magnetic disk surface by liding contact with the cleaning sheet, falling-away of the fibers from the cleaning sheet by sliding contact with the magnetic disk, and attaching of the fallen-away fibers to the magnetic disk or the magnetic head, thereby having an adverse effect on the recording-reproducing characteristics.
Thus, the so far available cleaning sheets have not satisfied the above two characteristics, and consequently have not exhibited satisfactory functions as a cleaning sheet.